This image is an illustration of the recursive process of generating a Menger sponge, which is a fractal object. It shows the first three iterations of an infinite process. The illustration was created by using a simple "Lindenmayer system" (L-system).

The number of cubes at a given iteration is ${\displaystyle 20^{n}}$, where ${\displaystyle n}$ is the number of iterations performed on the first cube:

At the start, no iterations have been performed so ${\displaystyle 20^{0}=1}$. The image shows a total of 8,421 cubes (the sum of all four steps).

See also:

• en:L-system
• en:Menger sponge

Image: User:Solkoll. Public domainPublic domainfalsefalse 此作品已由其作者，Solkoll，釋出至公有領域。此授權條款在全世界均適用。 這可能在某些國家不合法，如果是的話： Solkoll授予任何人有權利使用此作品於任何用途，除受法律約束外，不受任何限制。 More 3D fractals from my tool: Image:3D Cantor set.jpg Image:3D Julia-set (IFS 001).jpg Image:Dragon trees.jpg Image:Fractal tree (Plate b - 1).jpg Image:Fractal tree (Plate b - 2).jpg Image:Fractal tree (Plate b - 3).jpg Image:Fractal weeds.jpg Image:Harter-Heighways dragon curve (3D twist).jpg Image:Heavy Lévy.jpg Image:Julia set (reversed formula 3D).jpg Image:Lévy's C curve (3D-goggles).jpg Image:Lévy C curve (3D-twist).jpg Image:Menger sponge (IFS).jpg Image:Menger sponge (Level 1-4).jpg Image:Sierpinski pyramid.jpg Image:Sierpinski tetrahedron.jpg Image:Sierpinski tetrahedron (Detail).jpg All freaktal images are from self-written tools. Linear fractals from my : "3D IFS studio" and "3D DTIFS" (dragon trees), non-linear IFS from "3D RJIFS" (3D rev Julia).

See also: Solkoll & Solkoll 2D